Dreaded drivers floor water leak (1 Viewer)

[caladin]

First good rain in a while, went out and found this on drivers floor mat. It was a puddle before I mopped it up.

I swear I remember reading about this, and it being caused by a clog somewhere, but I can't remember where. My search fu failed.

I couldn't find anything under the dash that was wet, or inside the door threshold.

Carpet under mat was dry, so I figured it was dripping, not running down the wall.


There was the tiniest bit of water directly below the bottom right corner of my windscreen on the door seal, not sure if it was there before or driped from opening the door.

What are my likely culprits?

Thanks

 

[MDH33]

3 likely culprits are A-pillar seam, firewall seams, or cowl drain.

 

[SteveH]

Windshield corners (or gasket) are top on my list and the water ends up right there.

 

[caladin]

Windshield corners (or gasket) are top on my list and the water ends up right there.

Is there a good way to solve that short of having the windscreen removed and reinstalled with fresh gaskets?

Thanks,

 

[cps432]

Remove the fender and check the cowl drain. It funnels down from a 4-5” wide opening to a 1” tube for some reason and as leaves and pine needles get washed out of the cowl over time it clogs the down pipe. This causes water to sit in the cowl and rust. There is some seam sealer around the cowl/firewall seams and in my case it was dry as dust. The seams were rusted and I’m 99% certain water was entering the cabin there.

I have my engine out currently and decided to fix all my leaks before it starts snowing up here. I scrubbed the rust and scuffed the paint up. I used a rust converter to soak the seams where I was unable to reach. Let that dry for a day or two and then prime the bare metal/converted rust surface. I then used 3M seam sealer to stop water from penetrating the seams. I stopped short of sealing the bottom of the panels because I want water to run out if it ever does get between the sheet metal.

I know for certain I have a leak from the rain gutter and windshield on the passenger side because the headliner gets wet along the a pillar. I will deal with that next summer, but for now the cowl and firewall are leak free.

 

[cps432]

Is there a good way to solve that short of having the windscreen removed and reinstalled with fresh gaskets?

Thanks,

In a pinch you could carefully lift the corner of the gasket and shoot some RTV in there. It might get you through the winter.

Generally, the reason it’s leaking there is because water has gotten under the gasket and rusted a hole in the metal. Even if you pull the glass and install a new gasket with fresh sealant you will eventually end up with a leak if it’s rusted out at all. Heck, it doesn’t even have to be rusted through. Just needs to be bad enough that water runs under the gasket.

Next summer I will be pulling my glass and welding patches in the window sills all around my truck. I have a few sketchy spots myself.

 

[g-man]

Remove the access panel on the drivers side of the firewall up high. Then run a vacuum hose in there over toward the fender and down. See if you can clear it. Easy peasy 2 screws and done. The passenger side is more difficult to deal with. Another way to access the drain is to pull the side vent off the side of the fender. Again only 2 screws. Then reach in there and hank off the plastic drain tube. then run a coat hanger wire or other stiff wire up the metal drain opening.

If you don't have debris in the cowl, check the rain gutter for cracks in the seam sealer in the bottom of the drain. If you have cracks and rust you may have some holes. You can grind this out with a small abrasive disc on a die grinder or drill. Be careful to tape up the paint and not nick the paint on the roof. Then re-apply seam sealer in the rain gutter.

Lastly, you could have a leaking windshield gasket. If this is the case I'd guess you would have some moisture issues behind the dash.

 

[Moonglow96]

I had water coming in where the speaker wires go in the A pillar. There was no gasket so I just gummed it up with a wad of butyl and it seems to have worked. Also had it splashing in due to the card and moisture barrier being off of my driver door.